Dovetail joint



(Modelr) E. MARTER.

DOVETAIL JOINT.

No. 435,759. Patented Sept. 2, 1890.

; a will" "ll imam? w th [away a l ummboz UNITED STATES PATENT OFFICE.

EZRA MARTER, OF MISIIAXVAKA, INDIANA.

DOVETAIL JOINT.

SPECIFICATION forming part of Letters Patent No. 435,759, datedSeptember 2, 1890.

Application filed August 5, 1889. Serial No. 319,714. (ModeL) To allwhom it may concern:

Be it known that I, EZRA IWIARTER, a citizen of the United States,residing at Mishawaka, in the county of St. Joseph, State of Indiana,have invented certain new and useful Improvements in Dovetail Joints, ofwhich the following is a specification, reference being had therein tothe accompanying drawings.

This invention has relation to certain new and useful improvements indovetail joints; and it has for its object to provide a simple form ofjoint which shall be self-locking, working to look by movement from theinside outward, whereby any undue outward pressure upon the partsjointed will serve to more firmly bind them together. As an additionalprecaution against separation under any circumstances, I provide theinterior lockingpiece engaging opposite ends of the structure andserving to receive the pressure or strain.

The novelty resides in the peculiarities of construction and thecombinations, arrangements, and adaptations of parts, all as more fullyhereinafter described, shown in the drawings, and then particularlypointed outin the appended claims.

The invention is clearly illustrated in the accompanying drawings,which, with the letters of reference marked thereon, form a part of thisspecification, and in which Figure 1 is a plan of two adjacent partsconstructed to form my improved dovetail joint, the parts beingdisengaged, and sections thereof, said sections being taken upon thedotted lines shown in the plan. Fig. 2 is a side elevation of one of theparts with section on the dotted line thereof. Fig. 3 is an edge view ofthe male portion, having also a section thereof, the section being takenon the dotted lines of both views, illustrating a portion of thesupplemental locking-piece. Fig. 4 is a section through the line am ofFig. 5. Fig. 5 is a perspective view of portions of two parts united bymy improved joint with the supplemental locking-piece in place.

Like letters of reference refer to like parts throughout the severalviews.

Referring-to the details of construction by letter, A designates what Iterm the female portion, and B the male portion, of the joint 01' lock.The female portion A is formed at opposite ends with the mortises A,which are dovetailed in their exterior contour upon both sides of thepiece and upon the end, as shown, the inner faces of the mortises beingall inclined, the two opposite ones being undercut, as shown, the wall Aof the mortise being inclined at an angle of about forty-five degrees,so that the opening in the mortise upon the outer face of the femaleportion A is substantially one-half of the depth of that upon theinside.

The male portion B is formed with a rightangled proj eetion B, andformed with a groove 13*, as shown clearly in Figs. 1, 3, and 4. Thetenons B on this portion extend across the projection 13, as seen bestin the section in Fig. 3, and are dovetailed to correspond to thedovetail mortises in the female portion, said mortises being formed withan inclined portion B as seen in Figs. 3 and 4:, said incline extendingfrom the outer edge of the projection B to a point substantially midwaybetween the said edge of the projection and the outer face of theportion B, leaving a dove- 7 5 tail portion B of the same width as theopening on the outer face of the mortise in the female portion A.

In practice the tenons of the male portion are entered into the mortisesof the female portion from the inside and the male portion forcedoutward lengthwise of the female portion, and as it is pressed home ithas a movement in two directions-lengthwise of the female portion andalso in a direction at right angles thereto-until the parts are forcedhome, making a flush joint upon both exterior faces of the parts, theinclined portion 13* of the tenons of the male portion riding up theinclined face A of the mortises of 9c the female portion, serving todraw the parts into their proper position, and the greater the pressureupon the inside the more firmly will the parts be locked. The walls ofthe mortises, and also those of the tenons, being 5 all formed upon anincline, constitute awedge in all directions. A reverse movement of theparts upon each other is necessary to separate the parts A and 13. Inorder to strengthen the structure and form also an additional [00 lockfor the joint, I employ the locking-piece C, which extends across fromone side to the other and across the angle at the joint or union of thetwo parts A and 13, and which at its ends is halved out, as shown at O,the lips 0 thereof entering the grooves or channels B of the maleportions, theshoulder O impinging against the edge B of the projectionB, as shown in Figs. 3, 4, and 5. The

projection B forms the complement of the The parts constructed as abovedescribed are applicable to all uses in all places where itis desired tounite partsby a dovetail joint where there is any angular arrangement ofthe members whether in boxes, drawers, partitionsor other constructions.The ang'ular relation of the partsA and B is important, inasmuch as itserves to produce the locking effect by increased pressure on the parts.

Wherever in the description and claims I use the term inside I Wish tobe under stood as meaning the face of the parts from which the maleportion of the joint is entered. The parts united and locked in themanner above described are prevented from spreading. by the weight orpressure exerted thereagainst from the inside-as, for instance, Wherethe parts are employed in the construction of a box or other receptacle.

What I claim is 1-. The combination, With parts constructed to form adovetail joint working to look by movement from the inside out, of anunpivoted bodily-movable interior locking-piece extending across theangle at the joint and entered into one of the parts to prevent reversemovement of said parts, as set forth.

2. The combination,with one portion formed with dovetail mortises andthe interlocking portions formed With tenons engaging said mortises andwith channels B of a lockingpiece, as 0, having portions engaging saidchannels, as set forth.

3. The combination vith the female and the male portion interlockingtherewith and formed with extensions B and channels B of thelocking-piece formed with lip C and shoulder 0 as set forth.

4:. The combination, with the female portion having mortises, of themale portion having projection 13-, and tenons extending across saidprojections, substantially as described.

5. The combination, Withthe female portion having mortises, of the maleportion having projection B, and tenons extending across saidprojection, said tenons being formed with inclined portion B as setforth.

6. The combination, with the female portion formed with mortiseshavinginclined wall A of the male portionhaving projection B, and dovetailtenons extending across the projection and formed upon the inner facewith inclined portion B substantially as shown and described.

In testimony whereof I affix my signature in presence of two witnesses.

I EZRA MAR'LER. YVitnessesr J AGOB D. HENDERSON,

JosEPH. HENDERSON-

